Piano-player action



A. e. GULBRANS EN. PIANO PLAYER ACTION. APPLICATION FILED JUNE 3, I915.

Patented Aug. 10, 1920.

4 SHEETS-SHEET 2.

ZOE 03 W QF IIIIIIIII I IIIII 5 P I @fl I, '3

IIIIII. 17172671607 1 5L666: Gu/Zbmnsen 3 mm ww wn WHI I IHI I I IMH HH I I N T [I m% I IIIIIIIIIIIIIIIII I L I@.

@ @I QM I ffhiys A. G. GULBRANSEN.

PIANO PLAYER ACTION.

APPLICATION FILED JUNE 3. 1915.

1,349,273. Patented Aug. 10,1920.

4 SHEETSSHEET 3.

TO TRACKER- BAR InUGnior fijcd 67', Gulbmnsen A. G. GULBRANSEN.

PIANO PLAYER ACTION.

APPLICATION FILED JUNE 3.1915.

Patented Aug. 10,1920.

4 SHEETS-SHEET 4.

i I l I l l I l Invsnibr 142ml 6. Qumran/sen By M, MM

UNITED STATES PATENT OFFICE.

AXEL G. GULBRANSEN, OF CHICAGO, ILLINOIS, ASSIGNOR T0 GULBRANSEN-DICKINSON COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PIANO-PLAYER ACTION.

Application filed June 3, 1915.

To all whom it may concern:

Be it known that 1, Axnr. G. GULBRANSEN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Piano-Player Actions, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to automatically operated musical instruments and has to do particularly with what are known as player pianos or piano players. It will be obvious that the device of my invention may be applied to organs as well as pianos and, in fact, to any musical instrument or other device operated in an analogous way. It will be understood that my invention is concerned with what has become known as the action that is, the operating means and need not, therefore, be limited to its application to any particular instrument.

In order to simplify this description I shall explain my invention and apply it to a player piano, particularly since some of the more limited features are really limited to a player piano and since, in general, the advantages which my invention secure are most pronounced in its application to such a structure.

As before indicated, my invention has particularly to do with the action, which term has become used in the art to signify the structure comprising the playing unit and the immediately associated parts. My invention has to do with that class of automatic instruments which is operated pneu inaticully and therefore these operating units or devices will be seen to be in the form of small bellows commonly known as pneumatics. One of these pneumatics is provided for each note on the piano to be struck and my invention is concerned with the construction of these pneumatics, the valve mechanism therefor, the connections to the power plant and the general assembly of the structure which may be termed a stack.

It is the object of my invention to provide a radically simplified, compact, and tight structure. By reason of the simplicity of the structure and the minimum number of parts employed, the possibility of leaks is practically, if not absolutely, elimi- Specification of Letters Patent.

Patented Aug. 10, 1920. Serial No. 31,815.

nated. lVhat has become known in the art as the vacuum chamber of the stack or action has been practically dispensed with, by means of my invention, and the resulting directness of the connection between the operating pneumatics and the power plant further contribute to the air tight feature of the structure and the effectiveness and simplicity of the operation.

My invention also relates to the mounting of the action in the case, as will be described.

My invention is illustrated in the accompanying drawings in which Figure 1 is a front elevational view of the upper part of a player piano, part of the casing being removed, showing the application of the structure of my invention thereto.

Fig. 2 is a more or less diagrammatic side view of the arrangement shown in Fig. 1.

Fig. 3 is a rear elevational view of the action.

Fig. 4: is an end elevational view of the action, part being shown in cross-section so as to clearly reveal the interior construction.

Fig. 5 is a detail view of a valve stem arrangement which will be referred to.

Fig. 6 is a plan viewof a portion of the action, part being shown in section.

Fig. 7 is an end view of the action and the associated casing parts, and

Figs. 8 and 9 are further detail views, Fig. 9 being a section on line 9--9 of Fig. 8.

Referring first to Figs. 1, 2, '7, 8 and 9, it will be seen that the piano case is shown at 7, the key bed of the piano being shown at 8 and side pieces being provided at 9, 9. The action of my invention is supported by the side pieces 9, 9, it being seen that the channel board 10, which I shall describe more specifically later, is secured to the side pieces 9, 9, by means of the screws 11, 11. It will be seen that this arrangement provides for the ready removal of the channel board and since the operating pneumatics are all carried by this channel board, it will be seen that the entire action may be immediately removed. The compactness of the action permits of it being so mounted that the keys K can be removed without removing the action.

Hinged to the top of the channel board 10 by means of the hinges 12, 12, is a bracket board 13, the nature of which is more clearly illustrated in Figs. 2 and 7. The bracket board 13 carries the roller box 14 in which the rollers 15 and 16 and the tracker board 17 are provided. The rollers are operated by means of pneumatic motor 18, the details of which I am not concerned with here. In order to simplify this description and illustration, I have shown the motor and the roller box arrangement in 'a most general way. It will be suliicient to point out that the tracker board 17 is connected with the action in a manner to be described presently.

A metal bracket 19 is secured to the back of the channel board and extends upwardly to engage the bracket board 13, one of these metal brackets being provided at each end of the channel board. The end of the bracket 19 is provided with ascrew 20 upon which a thumbnut 21 is screwed and it will outer position, its inner position being the normal position and its outer position being that which allords access to the mechanism behind the roller box. The links are pivoted to the back board at 23 and to the roller box at 23. 9'shows the linkages in plan, one of the links being provided with a foot 23 abutting the back board.

Referring now to liigs. 3 to 6, inclusive, it will be seen that the channel board 10 is a single integral member extending from end to end of the casing and consequently extendingentirely across all the striker rods which, in the piano construction, are disposed behind it, as indicated, ii -Fig. 5. This single integral member 10 is mortised at the rear side or the top throughout the entire length thereof, as illustrated at 24, and a series oi channels arranged longitudinally of the board pass down from this mortised portion to the various pneumatic mechanisms, as will be described, these channels being indicated at 25. For each channel 25 a smaller channel 26 is also provided, each channel 26' being preferably in the same transverse plane with its "corresponding channel 25,'as illustrated in Fig. 6. This channel26 is drilled down from the 'very'top oi the board, as illustrated in Fig. 5, and the top of the channel is plugged by means of the member 27. A

strip 28 is secured, preferably by means or" glue, and other means in addition probably, to the rear face of the board 10 in the mortised portion and a board 29 is secured over this strip and the rear face of the board 10, as illustrated in Fig. fl, so as to form the longitudinal channel 30 which runs from end to end, the end however being properly plugged up or'stopped up so as to makethe channel 30 air-tight. It will thus be seen that the channel 30 is in direct communication with all the passage-ways 25 which lead downwardly therefrom.

transverse channel 31 is drilled through the board 29, the strip 23, and part of the board 10 into each of the passage ways 26 and a tube, preferably oi rubber, illustrated at 32, extends from each of the channels'31 to a corresponding opening in the tracker board 1.7. It will be under stood that the passing of the note sheet over the tracker board controls the momen tary ortemporary admission of air to the passageway 31 and the connected parts below.

The actuating pneumatics are arranged in three rows and are staggered in their vertical relationto each other so as to bring each of them in proper registry with the corresponding striker rods of the piano mechanism. Three boards, each or" which may be termed a channel and valve board, are secured edgewise to the rear face of the channel board lO; that is, the channel and valve boards liein horizontal position and extend rearwardly from the channel board 10, being placed one above the other. These channel and valve boards extend'nearly the entire length oii tie channel board 10 and each of them supports an entire row of actuating pncumatics. The channel and valve boards are illustrated at 33 and it will be seen that each of them'issecured to the rear face of the channel'board 10 by means of long screws 34:, 3 at each end thereof, these channel and valve boards being prefably also firmly andtightly glued to the ace of the channel board 10.

Each of the actuating pneumatics comprises a stationary board'35 and amovable board 36 which is hinged'at its forward end to the stationary board 35 by means of a by means of the bellows cloth 33. The movable boarc 36 has areal-ward extension 39 for engagement with the abutment member 40 carried by the corresponding striker rod 41. A description of one of these pneumatics will suflice, since all the actuating pneumatics are of the same construction, each being disposed in position to actuate its corresponding striker rod.

Each of the boards 35 is firmly secured in proper position to the under side of the proper valve and channel boards 33, as clearly illustrated in the drawing. By reference to Fig. 4, it will be seen that each of the boards 35 pro'vides'a diaphragm chamber 4-2 which is covered by the diaphragm 43, this chamber 4-2 being connected with its corresponding passageway 26 by means of the L-shaped passageway 44 in the board 35,

. the passageway 45 in the board 33 and the pasageway 46 in the board 10. The diaphragm 43 is shown in its lowermost position in Fig. 4 and it will be understood that the space above it is ample for its movement to the opposite extreme. In axial alinement with the diaphragm 43 the board 33 is provided with an opening 47 and a valve chamber 48. A valve seat ring 49 is disposed tightly in the top of the opening 47, this ring being preferably of metal so as to form an effective valve seat. A head 50 engaged by, and either secured or not secured to the diaphragm 43 is carried by a valve stem 51 which passes upwardly though the opening 49 and through the valve seat ring and at the top is provided with the valve member 52. This valve stem 51 is illustrated in detail in Fig. 5 where it will be seen that it is effectively guided in the valve seat ring while at the same time providing for ample air passage thereby. It will now be understood that when the diaphragm is in its lowermost position, the valve 52 rests upon the valve seat ring and when the diaphragm is in its uppermost position the valve 52 is raised so as to make communication between the pasageway or hole 47 and the valve chamber 48.

A passageway 53 connects theopening 47 with the aperture 54 in the channel board 10, which aperture, in turn, connects with a corresponding passageway or channel 25. The valve chamber 48 connects with the interior of the corresponding actuating pneumatic by means of two passageways 55, 55. The valve chamber 48 is provided with a cover piece 56 which has the opening 57 for the free admission of air. An arch member 58 open at the ends passes from end to end of the top channel and valve board 33 and protects all the air inlets 57, 57. The inlets 57, 57 of the lower boards 33, 33, are protected by the boards above them and therefore as to these lower boards, a second arch member is not necessary. It will now be understood that for each of the actuatin pneumatics the corresponding channel an valve board 33 is provided with a system of channels or passageways comprising the parts 47, 48, 49, 45, 53, 55, 56 and 57 and for each of these systems a valve 52, valve stem.

51, and disk 50 is provided. The arrangement which has been described is of simple construction. There is no need for complicated machinery to form the various passageways in the boards 33, 33, this simplicity being contributed to by the provision of the diaphragm chamber in the board 35 which is formed completely before being secured to the under side of the board 33.

It will now be understood that normally the diaphragm 43 is in its lowermost position. This position is assured by gravity and also by the fact that the passageway 26 is bled from the channel 30 through a very restricted aperture 59 in a metal thimble 60 secured in an opening 61, drilled in the board 10 between the passageways 26 and 30. The thimble is inserted through an opening 62 which, after construction, is closed by means of a strip of air-tight material indicated at'63. As indicated in Fig. 3, the passageway 30 is connected with the power plant by means of a suction tube 64, this being diagrammatically shown in Fig. 2 where the dotted line 65 indicates the connection to the power bellows 66, now well known in the art. It will thus be seen that a constant vacuum is maintained in the passageway 26 and the connecting passageways, including the diaphragm chamber below the diaphragm 43 so long as air is not admitted through the tracker bar into the corresponding passageway 31. Just as soon as air is admitted through an opening in the notesheet, pressure is transmitted down through the passageways 31, 26, 46, 45, 44 and since a constant vacuum is maintained above the diaphragm by way of thepassageways 47, 53, 54, 25 and 30, the diaphragm rises to its uppermost position. This changes the position of the valve 52. Normally this valve rests upon its seat and the actuating pneumatic is connected directly with the atmosphere through the passageway 55, the valve chamber 48 and the opening 57. WVhen, however, the valve 52 is moved to its uppermost position, it engages the under side of the disk 56 and closes the opening 57 This shuts off the access of the atmosphere and directly connects the actuating pneumatic with suction. It will be obvious that this collapses the pneumatic and raises the extension 39 so that it will in turn raise the abutment member 40 and consequently the striker rod 41 to sound the corresponding note. \Vhen the admission of the atmosphere to the passage 31 has again been cut off by the action of the note sheet, the suction again operates through the aperture to reduce the pressure below the diaphragm 43. This again equalizes the pressure on both sides of the diaphragm and gravity brings down the valve 52 so as to cut off the connection between the suction means and the actuating pneumatic and, instead, connects the actuating pneumatic with the atmosphere, so as to permit its extension. An adjusting screw 64 is provided to determine the throw of the movable board of the actuating pneumatic.

It will be seen that the channel board 10 is readily constructed, being simply a matter of drilling a system of channels so that the connection to the suction means is secured without the intervention of the usual vacuum chamber. It will also be seen that the boards 33, 33, are readily constructed and that the number oi parts is at amlnimum. l have found by experiment and test that with this kind oi a structure the actuating pneumatics operate with especial directness and eliiciency.

By my invention the moving medium between the power plant and the actuating pneumatic is at a volumetric minimum, that is, the capacity of the connecting passages is at a minimum and therefore the total expansion possible is reduced toa minimum. Packed joints are entirely eliminated and the boards 33, 33, are ei'lective in keeping the'board 10 from warping out of shape.

I claim as new and desire to secure by Letters Patent r 1. In combination, a channel board having" a plurality of independent channels therein, a longitudinal channel and a plurality of channels extending from and disposed below said longitudinal channel, a plurality of actuating pneumatics each having a passageway connecting with one of said third named channels, a valve in each said passageway,

said mortise, a plurality of actuating. pneumatics each having a passageway con necting withone of said third named channels, a valve in each said passageway, a

diaphragm for operating eachsaid valve, and a diaphragm chamber adjacent each said diaphragm, each diaphragm chamber bein connected with one of said firstnamed independent channels.

, 3. In combination, a channel board having a plurality of independent channels therein,

a longitudinal channel and a plurality of channels extending from and disposed below said longitudinal channel, a plurality of actuating pneumatics each having a passageway connecting with one of said third named channels, a valve in each said passageway, said pneumatics being normally open to the atmosphere and said valve operating to close off the atmosphere when it moves to open said passageway, a diaphragm for operating eachfsaid valve, and a diaphragm chamber adjacent each said diaphragm, each dia phragm chamber being connected with one of said first named independent channels.

i. In combination, a channel board having a plurality oi 'independent channels therein, a longitudinal channel and a plurality of channels extending from and disposed below said longitudinal channel, a plurality of actuating pneumatics each having a passageway connecting with one of said third named channels, a valve in each said passageway, a diaphragm for operating each said valve, a diaphragm chamber adjacent each said diaphragm,each diaphragm chamber being connected with one of said first named independent channels, and a bleeder between each independent channel and said longitu dinal channel. I

5.1n combination, a channel board. having a plurality of independent channels therein, a longitudinal. channel and a pinrality of channels extending from and disposed below said longitudinal channels, a

plurality of actuating pneumatics each having a passageway connection with one of said third named channels, a valve in each said passageway,a diaphragm for operating each said valve, a diaphragm chamber adjacent each said diaphragnneach diaphragm chamber being connected with one of said first named independent channels, and an opening between each independent channel and said longitudinal channel, an outer access aperture in line with said opening, and a thimble providing a restricted vent disposed in said opening.

6. In combination channel board having a plurality of independent channels therein, longitudinal channel and a plurality of channels extendin from and disposed be-' low saidlongitudinal channel, each of said independent channels being connected with a traclzer'bar openingand said longitudinal channel being connected with a source of" suction, a plurality of actuating pneuniatics eachhavin a. passageway connecting with one-of said third named channels, a valve in each said passageway, a diaphragm for operating each said valve, and a diaphragm chamber adjacent each said oiaphragm, each diaphragm chamber being connected with one of said first named independent channels.

7. In combination a channelboard, a board secured to and extending laterally therefrom, a pluralityoit similar valve chambers and respective passageways leading thereto and therefrom in said second named board, a plurality of pneumatics, each comprising a stationary board and a movable board, the stationary board of each being secured to the laterally extending board, diaphragm chamber in each said stationary board, diapl'i'ragm in each said diaphragm chamber, and a valve carried in each s id valve chamber and engaged and operated by said diaphragm to control said passag ways.

S. In combination, a channel board, a

board secured to and extending laterally therefrom, a plurality of similar valve chambers and respective passageways leading thereto and therefrom in said second named board, a plurality of Pneumatics, each comprising a stationary board and a movable board, the stationary board of each being secured to the laterally extending board, a diaphragm chamber in each said stationary board, a diaphragm in each said diaphragm chamber, a valve carried in each said valve chamber and engaged and operated by said diaphragm to control said passageways, each said valve chamber having an atmosphere inlet and said valve operating to alternately connect said pneumatic With the atmosphere and with a channel in said channel board.

In Witness whereof I hereunto subscribe my name this 29th day of May, A. D. 1915.

AXEL G. GULBRANSEN. 

